Question 131032
to solve x^2=225

rewrite the formula to x^2-225=0

x^2-15^2=0

using formula, a^2-b^2 = (a+b)(a-b)

then x^2-15^2=0 become

(x+15)(x-15) =0

so the solutions are x=15 or x=-15.

Remember when u are solving quadratic equation, you should not just take square root of both side. You should always keep the x^2 until u have simplified the other term. so use the quadratic formula to find the solution.